A vehicle hit pedestrians in London and there are "a number of casualties being worked on at the scene," according to authorities.

LONDON (CNN) –(CNN) — The man suspected of driving a van into a crowd of worshippers near a mosque in north London’s Finsbury Park has been identified as Darren Osbourne of Cardiff, multiple media outlets in the UK said Monday.

Eyewitnesses reported chaotic scenes as the incident unfolded just after midnight, when worshipers had finished evening Ramadan prayers.

A 48-year-old man was wrestled to the ground by members of the public and then arrested at the scene on suspicion of attempted murder, London’s Metropolitan police said.

“This is being treated as a terrorist attack and the Counter-Terrorism Command is investigating,” said Neil Basu, senior national coordinator for terrorism at the Met. All the victims were Muslim, he said.

A vehicle hit pedestrians in London and there are “a number of casualties being worked on at the scene,” according to authorities.

Latest developments

Police say they believe there was only one man in the van.

An imam stopped the crowd from hitting and kicking the attacker.

Witnesses saw a man underneath the van.

Eight people were hospitalized, all Muslim.

Van appears to be a hire vehicle from a company in Wales.

The van rammed into the worshipers on Seven Sisters Road, a busy thoroughfare in Finsbury Park, north London, near a Muslim community center and a mosque.

Basu confirmed witness accounts that the man found dead at the scene was already receiving first aid when the attack happened, adding it was unclear whether he died as a result of the attack. Eight other people were taken to hospital, two of whom were seriously injured, he said. Two people were treated at the scene.

Muslim Welfare House CEO Toufik Kacimi said the attacker shouted “I did my bit, you deserve it.” An imam prevented people from taking revenge on the man, he said.

Police believed that the attacker acted alone, despite earlier reports from witnesses, who had said they saw two other people flee the scene.

Prime Minister Theresa May will chair an emergency meeting on Monday morning. “All my thoughts are with the victims, their families and the emergency services on the scene,” she said.

London Mayor Sadiq Khan called the incident a “horrific terror attack.” “We don’t yet know the full details, but this was clearly a deliberate attack on innocent Londoners, many of whom were finishing prayers during the holy month of Ramadan,” Khan said.

The assault comes on the heels of another attack at London Bridge, in which three men rammed a van into pedestrians and went on a stabbing spree at nearby bars and restaurants, killing eight people. Monday’s attack is the third in London since March involving a vehicle as a weapon against pedestrians.

Emotions are high in the UK in the wake of a series of deadly terrorist attacks and a fire at a London apartment building that killed dozens. Basu said it was a “challenging” time for London and that the emergency services were stretched.

What happened

Witnesses told CNN they saw a van driving at high speed along Seven Sisters Road after worshipers had attended late-night prayers at the Finsbury Park Mosque.

Abdikadir Warfa said the van turned into an alleyway and hit a number of people before coming to a stop. Images from the scene show a white van wedged against a traffic barrier at the dead end of a street.

“I saw a man, he was underneath the van,” Warfa said, who described how his friends tried to lift the van to free him.

He said as he attended the injured, others grappled with the driver as he tried to run away.

Ratib Al-Sulaman was sitting two minutes away when the incident occurred.

“Some big van … crushing the people in the mosque. So we just run straight away, I see police, ambulance, people lying on the floor, and a van as well,” said Sulaman.

Both Warfa and Sulaman said there were three people originally in the van, and that two had run away. Police say they are investigating these reports but believe that only one person carried out the attack.

Saeed Hashi described how he fought with the driver, and how he and two others held him to the ground for 10 minutes as they waited for police to arrive.

“He punched me in the head,” Hashi said, showing his bruises.

Mohammed Abdul said: “I saw something that was horrendous, something we should not see the in the 21st Century, something we should not see in the last 10 days of Ramadan.”

Police have not named the man arrested, but the van bears the logo and phone number for Pontyclun Van Hire in south Wales. CNN spoke to a man at the company, who said he was the owner but declined to give his name. He said police had instructed him not to speak to the media.

Warnings of anti-Islamic attacks

A statement released by the Muslim Council of Britain (MCB) condemned what it described as a “terror attack.”

“During the night, ordinary British citizens were set upon while they were going about their lives, completing their night worship. My prayers are with the victims and their families,” read the statement.

Tell MAMA, an anti-Islamophobia group, had visited Muslim Welfare House on Friday last week to inform the community about the need to report anti-Muslim hate incidents and to consider their safety during Ramadan.

“Ramadan is a time when Muslims are more visible and when there are larger congregations who attend late at night to pray after opening their fasts. Mosque safety needs to be stepped up and this includes entry and exit points,” it said in a statement.

Finsbury Park, in the London Borough of Islington, is a bustling, diverse area of north London with a strong Muslim community.

On May 22, a suicide attack killed 22 people and injured nearly 60 after an Ariana Grande concert in Manchester. The attacker was motivated by Islamist extremism, police said.

The London Bridge attack was on June 3. That attack also appeared inspired by Islamist extremism.

The head of Tell MAMA, Fiyaz Mughal, warned of reprisal attacks against Muslims following major Islamist terrorist incidents.

“We saw that very clearly after Manchester, a very high peak. We saw that clearly after London Bridge,” he said.